Bioavailability of selenium from bovine milk as assessed in subjects with ileostomy

Objective: To assess the absorption of dietary selenium in humans, especially of milk selenium. Design: 1-day meal studies in subjects with ileostomy. Setting: Hospital outpatient clinics. Subjects: Three subjects in the pilot study and nine subjects in the main study ( eight men/four women). Intervention: Different beverages, 1 l/day, were given in addition to basal diets ( soft drink, 1 week; low-fat milk, 3 weeks; fermented low-fat milk, 3 weeks and soft drink, 1 week). Ileostomy effluents were collected during the last 2 days in each of the four periods. Results: On days when the subjects were given 1 l of low-fat milk, the estimated fractional absorption of total dietary selenium was 65.5 (2.3)% ( mean (s. d.), n = 18), which was similar to the value when fermented low-fat milk was given (64.1 (3.2)%). However, both the calculated amount of milk selenium absorbed (10.9 (2.4) vs 9.4 (1.7) mg selenium) and its fractional absorption (73.3 (16.1) vs 64.1 (11.2)%, n = 18) were significantly higher for milk than for fermented milk. Conclusions: Selenium from milk and other sources is well absorbed in subjects with ileostomy. The real absorption may be even higher than the values shown.